As an other-vehicle detection apparatus mounted on a vehicle, a driving assistance apparatus, and an other-vehicle detection method of the related art, for example, Patent Literature 1 discloses an approaching vehicle recognition device which detects the orientation of an approaching vehicle with respect to an own vehicle. The approaching vehicle recognition device detects the traveling sound of the other vehicle by a plurality of acoustic-electric converters disposed at a predetermined interval and determines the incoming direction of the traveling sound of the approaching vehicle by applying various processes to an acoustic signal corresponding to the traveling sound.